Nuprl Lemma : integer-sqrt-ext

∀x:ℕ. (∃r:ℕ [(((r * r) ≤ x) ∧ x < (r + 1) * (r + 1))])


Proof




Definitions occuring in Statement :  nat: ℕ,  less_than: a < b,  le: A ≤ B,  all: ∀x:A. B[x],  sq_exists: ∃x:A [B[x]],  and: P ∧ Q,  multiply: n * m,  add: n + m,  natural_number: $n
Definitions unfolded in proof :  member: t ∈ T,  exp: i^n,  primrec: primrec(n;b;c),  subtract: n - m,  fastexp: i^n,  efficient-exp-ext,  so_apply: x[s1;s2],  natrec: natrec,  genrec: genrec,  genrec-ap: genrec-ap,  integer-sqrt,  integer-nth-root,  div_nat_induction,  rem_bounds_1,  decidable__lt,  decidable__equal_int,  decidable__squash,  decidable__and,  decidable__less_than',  decidable__int_equal,  decidable_functionality,  squash_elim,  sq_stable_from_decidable,  any: any x,  iff_preserves_decidability,  sq_stable__from_stable,  stable__from_decidable,  uall: ∀[x:A]. B[x],  so_lambda: so_lambda(x,y,z,w.t[x; y; z; w]),  so_apply: x[s1;s2;s3;s4],  so_lambda: λ2x.t[x],  top: Top,  so_apply: x[s],  uimplies: b supposing a,  implies: P ⇒ Q,  has-value: (a)↓,  prop: ℙ
Lemmas referenced :  integer-sqrt,  lifting-strict-int_eq,  strict4-decide,  lifting-strict-decide,  lifting-strict-less,  cbv_sqequal,  has-value_wf_base,  efficient-exp-ext,  integer-nth-root,  div_nat_induction,  rem_bounds_1,  decidable__lt,  decidable__equal_int,  decidable__squash,  decidable__and,  decidable__less_than',  decidable__int_equal,  decidable_functionality,  squash_elim,  sq_stable_from_decidable,  iff_preserves_decidability,  sq_stable__from_stable,  stable__from_decidable
Rules used in proof :  introduction,  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  cut,  instantiate,  extract_by_obid,  hypothesis,  sqequalRule,  thin,  sqequalHypSubstitution,  equalityTransitivity,  equalitySymmetry,  isectElimination,  baseClosed,  isect_memberEquality,  voidElimination,  voidEquality,  independent_isectElimination,  baseApply,  closedConclusion,  hypothesisEquality,  lambdaFormation,  callbyvalueReduce

Latex:
\mforall{}x:\mBbbN{}.  (\mexists{}r:\mBbbN{}  [(((r  *  r)  \mleq{}  x)  \mwedge{}  x  <  (r  +  1)  *  (r  +  1))])



Date html generated: 2018_05_21-PM-07_52_25
Last ObjectModification: 2018_05_19-PM-04_50_03

Theory : general


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